60 BRITISH .FRESHWATER RH1ZOPODA. 



There is some similarity between N. tubnlata and 

 small forms of N. barbata, which are occasionally found 

 about 80 fji in length, especially if these are seen in oil-, 

 of-cloves or in Canada balsam, as in these media the 

 fine cils which cover the tests are invisible ; but its 

 tapering neck and less compression of the test serve 

 to distinguish them even if the cils are overlooked. 



& 



5. Nebela scotica Brown. 

 (Plate LXI, fig. 17; PL LXIII, figs. 3-7.) 



scotica 

 BROWN in Jrn. Linn. Soc.. Zool. XXXII (1911), pp. 79-80, pi. ix, 



ff. 5-8 ; in Scott, Natur. 1913, p. 207. 

 Nebela deiitistoma var. lagenifonnis 



PLAYFAIK, in Proc. Linn.' Soc. N. S. Wales. XLII, 4 (1918), p. 659, 

 pi. xxxix, f. 5. 



Test of medium size, grey in colour, pyriform, 

 moderately compressed, the short neck terminating in 

 a broadly-elliptical aperture ; the surface of the test 

 usually smooth but occasionally irregular, composed 

 of transparent colourles's scales of various shapes, 

 occasionally imbricated; plasma and pseudopodia 

 normal. 



Length 78-82 /x; breadth 5759 /x; aperture 18-19 /A; 

 thickness 40 p.. 



Habitat. Sphagnum. 



ENGLAND. Westmorland (ttroini). 

 SCOTLAND. Ben Ledi, Perthshire (Brown). 



It is questionable if it would not be more appropriate 

 to record this species as a form or variety of N. dentis- 

 toma Penard, as in the case of a very similar American 

 form, N. dentistoma var. Jacnstri.s Wailes,* which is 

 140-200 /A in length but of similar form and propor- 

 tions. N. dentistomn is remarkable for its polymorphic 

 tendencies, the test varying in form from elongate- 

 ovoid to nearly circular, in this latter case being often 

 similar to N. acolia Cash. 



* ' Jcnirn. Linn. Soc., Zool.' vol. xxii, p. 137 (1912). 



